Stable hydrogen peroxid and method of making the same.



ED STATES PATENT onrre.

OTTO LIEBKNECHT AND ALOIS SCHAIDHAUF, OF FRANKFORT-ON-THiE-MAIN,GERMANY, ASSIGNORS TO ROESSLER AND HASSLACHER CHEMICAL COMPANY, OFNEW'YORK,

N. Y., A CORPORATION OF NEW YORK.

STABLE HYDROGEN PEROXID AND METHOD OF MAKING THE SAME.

No Drawing.

To aZZwhom it may concern:

Be it known that we, OTTO LIEBKNECHT and Arms SCHAIDIIAUF, both subjectsof the German Emperor, and residents of Frankfort-on-thc-Main, Germany,have invented. certain new and useful Improvements in Stable HydrogenPeroxid and Methods of Making the Same, of which the following is aspecification.

This invention relates to a stable hydrogen peroxid and method of makingthe same.

The problem of preserving the stability of solutions containing oxygenin available form, or carrying such oxygen, as fer-m stance of hydrogenperoxid solution is very important.

Hydrogen-peroxid solutions are used for many industrial purposes. Thougha great many chemicals have been suggested to produce the stabilizingeffect on the hydrogen peroxid solutions the latter are usually wantingfor some reason, in so far as the stabilizin agent mostly creates anundesirable e ect on the other substances with which the hydrogenper'oxid is brought into relation. Thus the nature of a suitablestabilizing agent for hydrogen-peroxid solution is very important. Up tonow these stabilizing agents have mostly taken effect I when thehydrogen peroxid. solution has been of either neutral or acid reaction,very few of these agents working in an alkaline solution.

We have now discovered a process for stabilizing any hydrogen peroxidsolution and other solutions containing oxygen in available formimmaterial of the nature of its reaction. We have found that afar-reaching importance must be attributed to the insoluble tincompounds, especially to stannic acid, in regard to their effect onhydrogen peroxid as well as other substances containing oxygen inavailable form.

The tin compounds do not behave indifferently toward alkaline hydrogenperoxid solutions, but act in a most favorable way on their stability,regardle$ of whether these solutions are of acid, neutral or alkalinere- Serial No. 764,931.

action. It is to be especially poted that the solutions formed by theaddition of tin compounds are immune to the decomposing action ofcatalyzers of any kind, the presence of small amounts only of such tincompounds being necessary to produce this effect. The hydrogen peroxidmay be stored in vessels of any kind if any of such tin compounds ispresent, or it may be forwarded or used, without danger ofdecomposition, incurring loss of oxygen and regardless of whether it isof alkaline, acid or neutral reaction.

The etliciency of the tin compound even goes so far that hydrogenperoxid solutions, already being in the state of decomposition,

may be saved although it has been believed up to now that such solutionsare hopelessly lost. 'It' must furthermore be noted that thisstabilizing effect of the insoluble tin compounds is produced by suchextremely small quantities that the price of the product is notinfluenced in any way thereby.

Our new process posseses a special merit in the fact that it does notrequire the absence of catalyzers in the solution or making forinstance, an alkaline reaction of the bath a condition for the successof the bath. The followin example serves to illustrate our invention: eadd to a 21% hydrogen peroxid solution, containing for instance 2 gramsof sodium hydrate per liter and therefore showing alkaline reaction,about 0.1 gram of precipitated stannic acid. A like alkaline solutionwithout the addition of stannic acid was heated up to 65 C. and wascompletely decomposed after two Patented Jan..30, 1am.

hours, whereas a solution containing stannic acid, which was treatedunder the same circumstances and for the same length of time stillshowed 91.2% of the hydrogen peroxid. The same stabilizing effect may bealso obtained in neutral or acid hydrogen peroxid solutions as seen fromthe fol-' the percentage by weight, thus ind1cating 100 the respectiveconcentration of hydrogen peroxid 'at the various times.) Acid hydrogenperoxid solucggn, containing 1% sulfuric a Neutral hydrogen-peroxidsolution.

The applied solution, containing 1% sulfuric acid, was carefullyneutralized.

After After After Begin- 5 h ms further further ning. t 8 16 hours 6hours 8 at 55. at 90".

100 cc. H 0: neutralized 16.8 7.75 7.35 6.95

with 4 cc. 5.5m NaOH.. 16.8 6.9 6.2 6. 0

100 cc. 11,0 neutralized 16.85 17.4 17.3 16.85 i gg i fig 16.8 17.918.35 22.4

In all these cases the freshly precipitated stannic acid may besubstituted by metastannic acid or some tin salt which gives stannicacid, as for instance sodium-tin chlorid, sodium stannate or also bysome insoluble salt of stannic acid as for instance, stannophosphate. Aconsiderable stabilizing effect is also produced if tin ash (anhydrousstannic acid) is added to the hydrogen peroxid solutions. In case oneadds stannous oxid or its salts to hydrogen peroxid solutions the sameare of course oxidized to stannic acid or its salts and thus alsoproduce a stabilizing efi'ect in the sense of the present invention.Other solutions, which like hydrogen peroxid also contain oxygen inavailable form, behave in the same way as, for instance a solution of apersalt, such as a. perborate, which carries such oxygen. By theaddition of stannic acid etc. the oxidizing effect of the solutionscoming into consideration is not decreased; this fact is of considerablevalue for the various kinds of bleaching baths and represents a greatadvantage because a useless generation of oxygen is avoided thereby.

The degree of alkalinity may vary Within a wide range, the stabilizingeffect of the tin compounds not being lowered thereby. Furthermore thealkali material to be added to the solution may also greatly vary. Thusfor instance solutions containing hydrogen peroxid or perborate maysimultaneously be charged with considerable quantities of soap, waterglass and soda and even yet may be preserved by the addition of tincompounds, such as sodium-stannichlorid, so that they may be used withvery great success to bleach wool in copper vessels for instance.

We do not restrict ourselves to any of the details hereinabove givenfurther than the scope of the appended claims demand.

We claim:

1. The method of rendering a solution, containing substances carryingoxygen in available form, stable which consists in adding an insolubletin compound to the solution.

2. The method of rendering a hydrogen peroxid solution stable, whichconsists in adding an insoluble tin compound to said solution.

3. A solution containing a substance carrying oxygen in available formand an insoluble tin compound.

4. A hydrogen peroxid solution, containing an insoluble tin compound.

In testimony whereof We have signed our names to this specification inthe presence of two subscribing Witnesses.

' OTTO LIEBKNEOHT.

ALOIS SCHAIDHAUF.

Witnesses J EAN GRUND, CARL GRUND.

